How to Grow Kuromame Tsurunoko
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Kuromame Tsurunoko
Glycine max
vegetableKuromame Tsurunoko is a Japanese black soybean variety prized for its sweet flavor and tender texture when harvested at the edamame stage. This climbing vine variety produces clusters of small black pods containing nutrient-dense beans. It is traditionally used in Japanese cuisine and is more flavorful than common green edamame varieties.
When should you plant Kuromame Tsurunoko in your zone?
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Example Kuromame Tsurunoko timeline · Pittsburgh, PA (Zone 6b)
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Plant Kuromame Tsurunoko
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Kuromame Tsurunoko
Around Jul 21≈ 95 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Kuromame Tsurunoko dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 5-8; requires warm soil and frost-free period of at least 90-100 days
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Germination & Seedling
2-3 weeksSeeds sprout within 7-14 days. Seedlings emerge with cotyledons and develop first true leaves.
Ensure soil temperature is at least 60°F (preferably 70°F+). Keep soil consistently moist but not waterlogged. Thin seedlings if needed to proper spacing.
Vegetative Growth
3-4 weeksPlant develops climbing vines with compound leaves. Tendrils form and plant seeks support structure. Vigorous upward growth occurs.
Install sturdy trellis or support system early. Apply mulch around base to retain moisture and regulate soil temperature. Monitor for early pest activity. Begin light fertilization with balanced NPK.
Flowering
2-3 weeksSmall, delicate white or purple flowers appear in clusters along the vines. Flowers are self-fertile and transition to small green then black pods.
Maintain consistent watering during this critical stage. Ensure adequate sunlight for flower development. Avoid high-nitrogen fertilizer which promotes leaf growth over flowering.
Pod Development & Edamame Stage
2-3 weeksPods develop and fill with seeds. At 75-85 days, pods are bright green, tender, and beans are at peak sweetness for edamame harvest.
This is the optimal harvest window for edamame. Pods should be plump and beans tender when squeezed. Water consistently to prevent pod splitting.
Mature Bean Stage
2-3 weeksPods darken from green to black. Beans inside fully harden and are ready for dry harvest. Plant may begin to senesce.
Allow pods to fully darken if harvesting for dried beans. Stop watering to allow pods to dry. Harvest entire plant or pick mature black pods individually.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Hand-pick beetles, use netting, apply neem oil or insecticidal soap; avoid traps near plants
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Increase humidity through watering, spray with strong water stream, use miticide if severe
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Monitor regularly, spray with insecticidal soap or neem oil, encourage beneficial insects
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Row covers early season, hand-pick, apply spinosad if populations exceed threshold
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Ensure good air circulation, avoid wetting foliage, apply sulfur or fungicide if needed
Uses
Edamame snack
CulinaryKuromame are prized for edamame, boiled with salt and eaten as a nutritious snack or appetizer. The black variety has a distinctly sweeter, richer flavor compared to green edamame varieties, making it highly valued in Japanese cuisine. [source]
Dried bean cooking
CulinaryMature black soybeans can be dried and cooked for use in soups, rice dishes, and traditional Japanese bean preparations. They retain their sweet flavor and are often used in festive dishes. [source]
Nutritional supplementation
MedicinalBlack soybeans are rich in protein, isoflavones, and antioxidants. They have been used in traditional Asian medicine for supporting bone health and hormonal balance. [source]
Nitrogen fixation
HouseholdLike all legumes, Kuromame forms symbiotic relationships with nitrogen-fixing bacteria, naturally enriching the soil and reducing the need for synthetic nitrogen fertilizers. [source]
Traditional Japanese cuisine
CulinaryKuromame is used in traditional dishes such as kuromame-gohan (rice with black soybeans) and appears in ceremonial New Year's celebrations in Japan, symbolizing good fortune and health. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
For edamame: Harvest when pods are bright green, plump, and tender (75-90 days), usually in late summer. Pods snap easily and beans inside are creamy when pressed. For mature beans: Wait until pods turn black and rattle when shaken (100+ days). Harvest entire plant and dry, or pick individual mature pods. Pods contain 2-3 beans each.
Fun Facts
- 🌱 Kuromame Tsurunoko is a traditional Japanese landrace variety that has been cultivated for centuries, with 'tsurunoko' referring to its climbing vine growth habit (tsuru = vine, noko = child).
- 🌱 Black soybeans contain significantly higher levels of anthocyanins (the same antioxidants found in blueberries) compared to yellow soybeans, giving them their deep color and enhanced nutritional profile.
- 🌱 In Japan, eating kuromame on New Year's Day is considered a tradition for good health and longevity, often served in a special ceremonial dish called 'kuromame no nimono.'
Gardening Terms
New to gardening? Learn about terms used in this guide:
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